Technical Field
The present disclosure relates to an adapter and an optical connector coupling system.
Related Art
A ferrule assembly with a multi fiber lens has been known which includes two ferrules configured to hold a plurality of optical fibers and an adapter configured to accommodate therein the two ferrules with the two ferrules being arranged to face each other (for example, refer to Patent Document 1). In the ferrule assembly disclosed in Patent Document 1, the two ferrules are arranged to face each other so that end surfaces of the respective ferrules are contacted to each other, and are thus positioned with respect to each other.
In the meantime, in order to optically couple two optical interface parts having lenses optically coupled with the optical fibers, it is required to form a predetermined interval between the two optical interface parts. Therefore, it is necessary to arrange each optical interface part at a position recessed from the ferrule end surface.    [Patent Document 1] International Patent Application Publication No. WO 2012/174227
However, according to the ferrule of the ferrule assembly disclosed in Patent Document 1, since an optical interface surface is arranged at the position recessed from the ferrule end surface, it is difficult to remove the dust and the like accumulated on the optical interface surface, so that it is very troublesome to clean the optical interface surface. Due to this, the high load is caused as regards the maintenance of the ferrule. Also, according to the ferrule assembly, it is necessary to form a recess portion on the ferrule end surface.